1 =pod 2 3 =head1 NAME 4 5 openssl-dsa, 6 dsa - DSA key processing 7 8 =head1 SYNOPSIS 9 10 B<openssl> B<dsa> 11 [B<-help>] 12 [B<-inform PEM|DER>] 13 [B<-outform PEM|DER>] 14 [B<-in filename>] 15 [B<-passin arg>] 16 [B<-out filename>] 17 [B<-passout arg>] 18 [B<-aes128>] 19 [B<-aes192>] 20 [B<-aes256>] 21 [B<-aria128>] 22 [B<-aria192>] 23 [B<-aria256>] 24 [B<-camellia128>] 25 [B<-camellia192>] 26 [B<-camellia256>] 27 [B<-des>] 28 [B<-des3>] 29 [B<-idea>] 30 [B<-text>] 31 [B<-noout>] 32 [B<-modulus>] 33 [B<-pubin>] 34 [B<-pubout>] 35 [B<-engine id>] 36 37 =head1 DESCRIPTION 38 39 The B<dsa> command processes DSA keys. They can be converted between various 40 forms and their components printed out. B<Note> This command uses the 41 traditional SSLeay compatible format for private key encryption: newer 42 applications should use the more secure PKCS#8 format using the B<pkcs8> 43 44 =head1 OPTIONS 45 46 =over 4 47 48 =item B<-help> 49 50 Print out a usage message. 51 52 =item B<-inform DER|PEM> 53 54 This specifies the input format. The B<DER> option with a private key uses 55 an ASN1 DER encoded form of an ASN.1 SEQUENCE consisting of the values of 56 version (currently zero), p, q, g, the public and private key components 57 respectively as ASN.1 INTEGERs. When used with a public key it uses a 58 SubjectPublicKeyInfo structure: it is an error if the key is not DSA. 59 60 The B<PEM> form is the default format: it consists of the B<DER> format base64 61 encoded with additional header and footer lines. In the case of a private key 62 PKCS#8 format is also accepted. 63 64 =item B<-outform DER|PEM> 65 66 This specifies the output format, the options have the same meaning and default 67 as the B<-inform> option. 68 69 =item B<-in filename> 70 71 This specifies the input filename to read a key from or standard input if this 72 option is not specified. If the key is encrypted a pass phrase will be 73 prompted for. 74 75 =item B<-passin arg> 76 77 The input file password source. For more information about the format of B<arg> 78 see L<openssl(1)/Pass Phrase Options>. 79 80 =item B<-out filename> 81 82 This specifies the output filename to write a key to or standard output by 83 is not specified. If any encryption options are set then a pass phrase will be 84 prompted for. The output filename should B<not> be the same as the input 85 filename. 86 87 =item B<-passout arg> 88 89 The output file password source. For more information about the format of B<arg> 90 see L<openssl(1)/Pass Phrase Options>. 91 92 =item B<-aes128>, B<-aes192>, B<-aes256>, B<-aria128>, B<-aria192>, B<-aria256>, B<-camellia128>, B<-camellia192>, B<-camellia256>, B<-des>, B<-des3>, B<-idea> 93 94 These options encrypt the private key with the specified 95 cipher before outputting it. A pass phrase is prompted for. 96 If none of these options is specified the key is written in plain text. This 97 means that using the B<dsa> utility to read in an encrypted key with no 98 encryption option can be used to remove the pass phrase from a key, or by 99 setting the encryption options it can be use to add or change the pass phrase. 100 These options can only be used with PEM format output files. 101 102 =item B<-text> 103 104 Prints out the public, private key components and parameters. 105 106 =item B<-noout> 107 108 This option prevents output of the encoded version of the key. 109 110 =item B<-modulus> 111 112 This option prints out the value of the public key component of the key. 113 114 =item B<-pubin> 115 116 By default, a private key is read from the input file. With this option a 117 public key is read instead. 118 119 =item B<-pubout> 120 121 By default, a private key is output. With this option a public 122 key will be output instead. This option is automatically set if the input is 123 a public key. 124 125 =item B<-engine id> 126 127 Specifying an engine (by its unique B<id> string) will cause B<dsa> 128 to attempt to obtain a functional reference to the specified engine, 129 thus initialising it if needed. The engine will then be set as the default 130 for all available algorithms. 131 132 =back 133 134 =head1 NOTES 135 136 The PEM private key format uses the header and footer lines: 137 138 -----BEGIN DSA PRIVATE KEY----- 139 -----END DSA PRIVATE KEY----- 140 141 The PEM public key format uses the header and footer lines: 142 143 -----BEGIN PUBLIC KEY----- 144 -----END PUBLIC KEY----- 145 146 =head1 EXAMPLES 147 148 To remove the pass phrase on a DSA private key: 149 150 openssl dsa -in key.pem -out keyout.pem 151 152 To encrypt a private key using triple DES: 153 154 openssl dsa -in key.pem -des3 -out keyout.pem 155 156 To convert a private key from PEM to DER format: 157 158 openssl dsa -in key.pem -outform DER -out keyout.der 159 160 To print out the components of a private key to standard output: 161 162 openssl dsa -in key.pem -text -noout 163 164 To just output the public part of a private key: 165 166 openssl dsa -in key.pem -pubout -out pubkey.pem 167 168 =head1 SEE ALSO 169 170 L<dsaparam(1)>, L<gendsa(1)>, L<rsa(1)>, 171 L<genrsa(1)> 172 173 =head1 COPYRIGHT 174 175 Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved. 176 177 Licensed under the OpenSSL license (the "License"). You may not use 178 this file except in compliance with the License. You can obtain a copy 179 in the file LICENSE in the source distribution or at 180 L<https://www.openssl.org/source/license.html>. 181 182 =cut 183
Indexes created Mon Aug 03 00:25:36 UTC 2026